Demystifying 5G – Testing dynamic spectrum sharing (DSS) on a device

Summary

In the latest episode of 'Demystifying 5G,' the focus is on dynamic spectrum sharing (DSS) between 4G LTE and 5G New Radio. The presenter demonstrates a comprehensive testing setup using the Rohde & Schwarz CMW500 platform, illustrating how both technologies can share the same frequency band without interference. Key processes include registering a 5G device on the LTE network, performing ping tests to verify connectivity, and analyzing demodulated signals. This foundational work showcases the coexistence of LTE and 5G, paving the way for further exploration of DSS capabilities in future videos.

Takeaways

• 📡 Dynamic Spectrum Sharing (DSS) allows 4G LTE and 5G New Radio to share the same frequency band.
• 🔧 The test setup uses the CMW500 Rohde & Schwarz platform for 5G device testing combined with LTE functionality.
• 📊 The SIM Squares GUI emulates an LTE cell with 5 MHz of bandwidth alongside an NR cell in the same frequency band.
• 📈 The lock file analysis shows that MBSFN subframes are configured for broadcasting in dynamic spectrum sharing.
• 📱 The test involved registering an early 5G device with no DSS capabilities to ensure LTE connectivity.
• ✅ End-to-end connectivity was verified through a ping measurement after successful device registration.
• 🔍 The FSW signal and spectrum analyzer were used to demodulate the 5G NR signal for performance assessment.
• 📶 Incoming signals displayed synchronization signal blocks for 5G NR while LTE was actively transmitted.
• 💡 QPSK modulation was observed in the physical broadcast channel of 5G NR, while BPSK was used for synchronization signals.
• 🔄 The demonstration validated that LTE and NR can effectively share the same RF signal without disrupting LTE functionality.

Q & A

What is dynamic spectrum sharing (DSS)?

Dynamic spectrum sharing (DSS) is a technology that allows 4G LTE and 5G NR to share the same frequency band, enabling more efficient use of the spectrum.

What equipment was used in the test setup for the video?

The test setup utilized the Rohde & Schwarz CMW500 mobile radio test platform and the FSW signal and spectrum analyzer.

How does the presenter demonstrate the emulation of an LTE cell?

The presenter emulates an LTE cell using the CMW500 configured with 5 MHz of bandwidth and demonstrates its operation alongside 5G NR.

What is the significance of MBSFN subframes in DSS?

MBSFN (Multicast-Broadcast Single Frequency Network) subframes are essential for dynamic spectrum sharing as they allow for the broadcast of additional information without disrupting LTE services.

How does the presenter verify that the 5G device is connected successfully?

The presenter verifies the connection by performing a simple ping measurement, confirming that the device is registered and communicating with the LTE network.

What was the outcome of the initial tests conducted on the 5G device?

The initial tests validated that the LTE and 5G NR signals could coexist on the same frequency band without causing disruptions to each other.

What modulation schemes were observed in the signals during the testing?

QPSK (Quadrature Phase Shift Keying) was used for the physical broadcast channel in 5G NR, while BPSK (Binary Phase Shift Keying) was used for primary and secondary synchronization signals.

What does the presenter plan to explore in future videos?

In future videos, the presenter plans to test the actual dynamic spectrum sharing functionality further, specifically how LTE and 5G NR can share the frequency band.

Why is it important to ensure that LTE services are not disrupted during testing?

Ensuring that LTE services remain uninterrupted is crucial for maintaining user connectivity and service reliability while implementing new technologies like 5G.

What role does the FSW signal and spectrum analyzer play in the testing process?

The FSW signal and spectrum analyzer is used to demodulate the LTE and 5G NR signals, allowing for real-time analysis and verification of signal quality and performance.